May/June 2021

Which row shows how particles are arranged and how they move in a liquid?

Solids, liquids and gases

In two different experiments, an electric current was passed through concentrated aqueous sodium chloride and through molten lead(II) bromide. What would be observed in both experiments?

Electrolysis

Overhead electricity cables are made using steel core aluminium cables. Which statement explains the reason for using these cables?

Uses of metals

Complete combustion of propane is exothermic. The reaction equation is shown here. $\text{C}_3\text{H}_8 + 5\text{O}_2 \rightarrow 3\text{CO}_2 + 4\text{H}_2\text{O}$ Which energy-level diagram shows the complete combustion of propane?

Exothermic and endothermic reactions

What changes take place when hydrogen is combusted in oxygen?

Exothermic and endothermic reactions

Heating sulfur first causes a ......1...... change when it melts. If heating continues, sulfur then undergoes a ......2...... change, producing sulfur dioxide. Which words should be used in gaps 1 and 2?

Physical and chemical changes

Zinc reacts with an acid, giving off a gas. The gas volume is recorded at regular time intervals. The outcomes are displayed by curve Z. The experiment is carried out again with a catalyst present. Which curve represents the catalysed reaction?

Rate of reaction

Which of the following statements is correct?

Elements, compounds and mixtures

Three different tests are done on an aqueous solution of S. The observations are as follows. 1. Magnesium shows no reaction with the solution. 2. When ammonium sulfate is heated with the solution, a gas is released. 3. On addition to the solution, methyl orange becomes yellow. What substance is S?

The characteristic properties of acids and bases

Element X makes an oxide, XO, that neutralises sulfuric acid. Which row identifies X and XO?

The characteristic properties of acids and bases

Copper(II) sulfate is made by reacting excess copper(II) oxide with warm dilute sulfuric acid. Which purification method is used to obtain pure solid copper(II) sulfate from the reaction mixture?

Separation and purification

A mixture is being separated using the apparatus illustrated. Which mixture is it?

Separation and purification

The reactions of element M below are shown. When element M is burnt, it forms the oxide of M. This oxide is then dissolved in water to give a solution. On adding blue litmus, the solution turns red. When the oxide is added to purple acidified potassium manganate(VII), the solution becomes colourless. What is the identity of element M?

The characteristic properties of acids and bases

Element X belongs to Group II of the Periodic Table. Which of the following statements about X are correct?

Arrangement of elements

Why is helium chosen for filling balloons?

Solids, liquids and gases

Which row states the pattern in the properties of the elements in Group I as the group is descended?

Group I properties

An element has a melting point of $1455\,^{\circ}\text{C}$, a density of $8.90\,\text{g cm}^{-3}$ and forms a green chloride. In which part of the Periodic Table is this element located?

Arrangement of elements

The following properties of metal J are given. J does not react when placed in cold water. J does react with dilute hydrochloric acid. When the oxide of J is heated with carbon, no reaction takes place. What is J?

Reactivity series

Iron from a blast furnace is processed with oxygen and calcium oxide to produce steel. Which substances present in the iron are removed?

Extraction of metals

Which row identifies a use of the metal and gives the reason for its use?

Uses of metals

Ammonium chloride is warmed with aqueous sodium hydroxide. A gas is given off which turns damp universal indicator paper blue. Which gas is this?

Identification of ions and gases

Which two gases together account for about $99\%$ of clean, dry air?

Air quality and climate

Which of the following statements about paper chromatography is correct?

Chromatography

A student makes three claims about potassium nitrate, $\text{KNO}_3$. Which of these claims are correct?

Ions and ionic bonds

Which table row shows the uses of sulfur and sulfur dioxide?

Oxides

When a white solid Z is added to dilute hydrochloric acid, a gas is released. Heating compound Z strongly also produces the same gas. What is Z?

The characteristic properties of acids and bases

Some details about compound L are given below. L is an organic compound containing four hydrogen atoms. L dissolves in water. When an aqueous solution of L is added to copper(II) carbonate, a gas is produced. What is L?

Carboxylic acids

The structure of an organic molecule is displayed. Which functional groups are present in this molecule?

Formulae, functional groups and terminology

Which compounds are members of the same homologous series?

Formulae, functional groups and terminology

Which of these statements about alkanes is correct?

Alkanes

Which structure shows poly(ethene)?

Polymers

There are four organic compounds, P, Q, R and S. P is classed as an unsaturated hydrocarbon. Q burns, but is otherwise unreactive. R has a $\text{C--C}$ single bond together with a $\text{C{=}C}$ double bond. S undergoes addition polymerisation. Which of the compounds are alkenes?

Alkenes

Which of the following statements about petroleum fractions is correct?

Fuels

Element X contains 7 protons. Element Y contains 8 additional protons compared with X. Which statement about element Y is correct?

Atomic structure and the Periodic Table

Which substance counts as a natural polymer?

Polymers

A covalent molecule Q has just six shared electrons. What is Q?

Simple molecules and covalent bonds

Which row shows how an ionic bond is formed between a sodium atom and a chlorine atom?

Ions and ionic bonds

Which diagram illustrates the structure of an alloy?

Alloys and their properties

Methane reacts with oxygen when it burns, producing carbon dioxide and water. What is the balanced equation for this reaction?

Physical and chemical changes

Calculate the relative formula mass of magnesium nitrate, $\text{Mg(NO}_3)_2$.

Relative masses of atoms and molecules

When iodine is heated, it changes directly from a grey solid into a purple gas. What is this process called?

Solids, liquids and gases

In two separate experiments, an electric current was passed through concentrated aqueous sodium chloride and through molten lead(II) bromide. What would occur in both experiments?

Electrolysis

An aluminium reaction is shown. $\;x\text{Al} + y\text{O}_2 + 6\text{H}_2\text{O} \rightarrow x\text{Al(OH)}_3$ What values of $x$ and $y$ make the equation balanced?

Formulae

Four different fuels are burned to warm a beaker of water for the same length of time, using the apparatus shown. The water’s starting temperature and the temperature after heating by each fuel are measured. Which fuel gives out the greatest amount of heat energy?

Exothermic and endothermic reactions

Which substance is not employed as a fuel?

Fuels

When sulfur is heated, it experiences a ......1...... change as it melts. If heating continues, the sulfur then undergoes a ......2...... change and produces sulfur dioxide. Which words fill gaps 1 and 2?

Physical and chemical changes

An excess amount of calcium carbonate is allowed to react with dilute hydrochloric acid. At fixed time intervals, the volume of carbon dioxide formed is recorded. The findings are given for experiment 1. The experiment is then carried out again, with just one alteration to the reaction conditions. The findings for experiment 2 are shown. What alteration has been made in experiment 2?

Rate of reaction

This equation shows a reaction that may be reversed by altering the conditions. anhydrous cobalt(II) chloride + water $\rightleftharpoons$ hydrated cobalt(II) chloride. Which of the following statements is correct?

Reversible reactions and equilibrium

Which of the following statements about acids is correct?

The characteristic properties of acids and bases

Element X forms an oxide, XO, which neutralises sulfuric acid. Which row gives the description of X and XO?

Oxides

Which test is the correct one for the named gas?

Identification of ions and gases

Some sugar has become mixed with glass. How can a sample of the sugar in solid form be removed from the mixture?

Separation and purification

Three tests are carried out in order to identify the ions in aqueous solution X. Which ions are contained in X?

Identification of ions and gases

A section of the Periodic Table is shown. Which element is a non-metal and has the lowest melting point?

Arrangement of elements

Period 3 of the Periodic Table includes the elements from sodium to argon. Which statement about these elements is correct?

Arrangement of elements

The diagram indicates where elements E, F, G and H are located in the Periodic Table. Which of the following statements about elements E, F, G and H is correct?

Arrangement of elements

An element has a melting point of $1455\,^\circ\text{C}$, a density of $8.90\,\text{g cm}^{-3}$ and it produces a green chloride. In which part of the Periodic Table would this element be placed?

Arrangement of elements

The noble gases are located in Group VIII of the Periodic Table. Which statement accounts for their lack of reactivity?

Noble gases

Iron from a blast furnace is converted into steel by being treated with oxygen and calcium oxide. Which substances are removed from the iron?

Extraction of metals

Cobalt, manganese and chromium are all metals. • Cobalt(II) oxide is reduced by carbon to give cobalt metal. • Manganese(II) oxide does not react with carbon. • Chromium(II) oxide does not react with carbon. • Chromium does not react with water. • Manganese reacts with water. What is the sequence of reactivity for these metals?

Reactivity series

Iron is obtained from hematite, whereas aluminium is obtained from bauxite. Which of the following statements about the extraction processes are correct?

Extraction of metals

Which property of aluminium makes it suitable for use in food containers?

Uses of metals

Which statement concerning paper chromatography is correct?

Chromatography

Which substance is required for iron nails to rust?

Corrosion of metals

Which row gives the uses of sulfur and sulfur dioxide?

Oxides

Which substance is a diatomic covalent molecule that occurs in pure dry air?

Simple molecules and covalent bonds

The equations show two reactions, P and Q, involving lime (calcium oxide). P: $\text{CaO} + \text{SiO}_2 \rightarrow \text{CaSiO}_3$ Q: $\text{CaO} + \text{SO}_2 \rightarrow \text{CaSO}_3$ During which processes do these reactions take place?

Oxides

Which gas is the principal component of natural gas?

Fuels

Which compounds are members of the same homologous series?

Formulae, functional groups and terminology

Which of the following statements about alkanes is correct?

Alkanes

Which compound causes aqueous bromine to become decolourised?

Alkenes

What chemical equation represents the process of fermentation?

Alcohols

The flow chart illustrates how petroleum can be converted into a plastic. What are processes 1, 2 and 3?

Polymers

Element X contains 7 protons. Element Y has 8 additional protons compared with X. Which statement about element Y is correct?

Atomic structure and the Periodic Table

Which substance is classed as a natural polymer?

Polymers

Covalent molecule Q has only six shared electrons. What is the identity of Q?

Simple molecules and covalent bonds

What is the chemical formula of the product formed when sodium burns in chlorine gas?

Ions and ionic bonds

Chemical compounds made from a Group I element and a Group VII element have ionic bonds. In what way are the ionic bonds formed?

Ions and ionic bonds

Some details about particles P, Q, R and S are shown. The table lists the nucleon number, the number of neutrons and the number of electrons for each particle. Which two particles are isotopes of the same element?

Isotopes

Calculate the relative formula mass of magnesium nitrate, $\text{Mg(NO}_3)_2$.

Relative masses of atoms and molecules

A $1\,\text{cm}^3$ portion of substance X is collected. This is sample 1. X is then changed into another physical state, and a $1\,\text{cm}^3$ portion is collected. This is sample 2. Sample 2 has a greater number of particles in the $1\,\text{cm}^3$ than sample 1. Which process led to this rise in the number of particles in $1\,\text{cm}^3$?

Solids, liquids and gases

In two separate experiments, electricity was passed through concentrated aqueous sodium chloride and molten lead(II) bromide. What would occur in both experiments?

Electrolysis

The equation for the thermal decomposition of calcium carbonate is given below. $\text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2$ How much calcium oxide, in mass, is formed when $10\,\text{g}$ of calcium carbonate is heated?

The mole and the Avogadro constant

Heat energy transfer in chemical reactions may be represented by energy level diagrams. In which row is the description correct?

Exothermic and endothermic reactions

The equations for two reactions are given below. 1. $\text{CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}$ 2. $2\text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}$ Which statement about these reactions is correct?

Exothermic and endothermic reactions

As sulfur is heated, it first experiences a .....1..... change as it melts. If heating continues, the sulfur then undergoes a .....2..... change and produces sulfur dioxide. Which words fill gaps 1 and 2?

Physical and chemical changes

Copper(II) carbonate reacts with dilute sulfuric acid. Which conditions would give the highest rate of reaction?

Rate of reaction

Hydrated copper(II) sulfate is blue. On heating, it produces white anhydrous copper(II) sulfate. How can a sample of anhydrous copper(II) sulfate be converted into hydrated copper(II) sulfate?

Physical and chemical changes

Copper(II) oxide reacts with iron. The equation for this reaction is shown below. $3\text{CuO} + 2\text{Fe} \rightarrow 3\text{Cu} + \text{Fe}_2\text{O}_3$ Why may this reaction be described as the reduction of copper(II) oxide?

Redox

Element X produces an oxide, XO, which neutralises sulfuric acid. Which row correctly identifies X and XO?

Oxides

Which salt-preparation methods are appropriate for copper(II) chloride?

Preparation of salts

Under appropriate temperature and pressure conditions, solid carbon dioxide passes straight into the gaseous state. Carbon dioxide gas diffuses from an area of higher concentration to an area of lower concentration. Which row gives the names of these two processes?

Diffusion

A white solid, J, is examined and the observations are given below. Flame test: a red flame. Acidify with nitric acid and then add aqueous silver nitrate: a white precipitate. What is J?

Identification of ions and gases

Which statement about the Periodic Table is incorrect?

Arrangement of elements

Bromine and iodine are elements in Group VII of the Periodic Table. Which statement about these elements is correct?

Group VII properties

At room temperature and pressure, helium and neon are present as monoatomic gases. Statement 1: Helium and neon each have eight electrons in their outer shell. Statement 2: Helium and neon are chemically unreactive. Which choice is correct?

Noble gases

An element has a melting point of $1455\,^{\circ}\text{C}$, a density of $8.90\,\text{g cm}^{-3}$, and produces a green chloride. In which part of the Periodic Table is this element located?

Transition elements

Which statement correctly describes the reactivity of metals?

Reactivity series

Iron from a blast furnace is reacted with oxygen and calcium oxide to produce steel. Which substances are taken out of the iron?

Extraction of metals

Water is taken from reservoirs and passes through several treatment stages so that it becomes safe to drink. Which of the following statements about the stages are correct?

Water

Which gas is a pollutant in the air that leads to acid rain?

Air quality and climate

An NPK fertiliser is produced by combining two compounds. The first compound has the formula $(\text{NH}_4)_2\text{HPO}_4$. State the formula of the second compound.

Formulae

Which statement regarding paper chromatography is correct?

Chromatography

Which reaction does not take place during the extraction of iron from hematite in a blast furnace?

Extraction of metals

Which row gives the uses of sulfur and sulfur dioxide?

Elements, compounds and mixtures

Metal X conducts electricity well and is used in electrical wiring. Metal Y is used to produce an alloy that resists corrosion and is used for cutlery. Metal Z is light but strong and is used in the production of aircraft. What are X, Y and Z?

Uses of metals

Which of the following statements about calcium carbonate is correct?

Elements, compounds and mixtures

Which substance forms the largest part of natural gas?

Fuels

Which compounds are members of the same homologous series?

Formulae, functional groups and terminology

Which statement regarding alkanes is correct?

Alkanes

P, Q, R and S are organic compounds. P is produced when ethene reacts with steam. Q causes bromine water to lose its colour. R is a hydrocarbon; every bond in it is a single covalent bond. S is a waste product formed during digestion in animals. Which compounds are alkanes?

Alkanes

Which row gives the correct description of how ethanol is used?

Alcohols

Which diagram illustrates the conversion of ethene into ethanol?

Alcohols

Element X contains 7 protons. Element Y has 8 more protons than X. Which statement about element Y is correct?

Atomic structure and the Periodic Table

Which substance is a polymer that occurs naturally?

Polymers

A covalent molecule Q has only six shared electrons. Identify Q.

Simple molecules and covalent bonds

What apparatus is used to measure out exactly $25.00\,\text{cm}^3$ of hydrochloric acid?

Acid–base titrations

Which statement is correct about isotopes of one element?

Isotopes

Potassium combines with iodine to produce an ionic compound. $\text{2K} + \text{I}_2 \rightarrow \text{2KI}$ Which statements explain what occurs when potassium reacts with iodine?

Ions and ionic bonds

Calculate the relative formula mass of magnesium nitrate, $\text{Mg(NO}_3)_2$?

Relative masses of atoms and molecules